We recently upgraded from SQL Server 2005 to 2008 R2 and suddenly are getting intermittent 'Timeout expired' messages.
We have a handful of windows services that we run which periodically connect to the DB and flip a bit on or off. The DB operation is as trivial as it gets. The services do this on a periodic basis, such as every 15 minutes throughout the day.
After the switch to 2008R2, each of the services will have 1 or 2 of these 'Timeout expired' messages within a 24-hour period, and each of them at different times throughout the day.
Just for grins, I created a test program that executes the above operation on the db twice per second, and let it run for 4 hours. In one four hour stretch I did not see any timeouts. In another, I saw one. My only conclusion at this point is that the error has nothing to do with the number of calls, and I was unable to reliably force a timeout.
I would like to see if anyone can provide me some ideas on how to determine whether this is really a symptom of some other issue, such as network, etc.
We have 4 DBs on one virtualized server in a mirrored configuration. Nothing special, just a basic configuration. The DB servers are all on one physical server and the windows services are on a separate physical server within a virtualized environment. The main change was the upgrade to 2008R2. The upgrade consisted of detaching the DB files from 2005 and attaching them to 2008. That's it.
Thank you for any assistance you can provide.